 Davenport–Schinzel Sequences and Their Geometric Applications

Davenport–Schinzel sequences are a concept in combinatorial geometry and discrete mathematics. They provide a way to count sequences of certain elements that meet specific restrictions. The main idea is to consider sequences formed from a finite set of symbols, where certain pairs of symbols cannot appear as consecutive terms in the sequence. ### Definition A **Davenport–Schinzel sequence** is defined over a set of symbols and contains restrictions on how symbols can be repeated.